1. Field of the Invention
The present invention relates to a filament slide fastener, wherein fastener elements of the slide fastener are formed into coil or zigzag types from monofilament made of thermoplastic resin and a retroreflective function is applied to fastener element rows.
2. Description of the Related Art
There is a slide fastener having a retroreflective function, as disclosed in Japanese Patent Laid-open Publication No. 64-20806, comprising fastener elements made of synthetic resin by injection molding on side edges of fastener tapes, a hemispherical recessed hole and a reflector face formed in a surface of each the fastener element, and a glass bead with its lower half portion buried in the recessed hole using a transparent glass adhesive, the recessed hole having a larger diameter than the glass bead.
There is another slide fastener, as disclosed in Japanese Patent Publication No. 4-79242, comprising fastener elements mounted on side edges of fastener tapes and retroreflective tapes mounted on surfaces of the fastener elements in a longitudinal direction, the fastener elements being unitized bodies or of filament made of synthetic resin or being fastener elements made of metal by die-casting molding.
Also, there is another slide fastener, as disclosed in Japanese Patent Publication No. 7-110245, comprising an undercoating paint layer mounted on a surface of each filament fastener element, a metal coating layer with a thickness of approximately in a range of 500 to 1000 A mounted on a surface of the paint layer, and a skim coat paint layer mounted on a surface of the metal coating layer.
Further, there is still another slide fastener, as disclosed in Japanese Patent No. 2613802, comprising a metal coating layer with a thickness in a range of 0.001 to 1 .mu.m formed on a surface of each filament fastener element and a metal coating layer with a thickness of 0.01 .mu.m or more on a core string inserted inside the filament fastener element row to apply metallic gloss.
The above first conventional slide fastener having the retroreflective function can not be easily applied to filament fastener elements made of synthetic resin, because it is required to form a large number of hemispherical recessed hole to have the reflector faces on the surfaces of the fastener elements made of synthetic resin by injection molding.
The above second conventional retroreflective slide fastener is difficult to be applied to the filament fastener elements and a mounting thread, because the retroreflective tape is mounted on the surfaces of the various fastener elements in the longitudinal direction by bonding, fusing, or sewing.
The above third and fourth conventional slide fasteners include the filament fastener elements having on their surfaces the metal coating layers to have metallic gloss, but do not have a retroreflective function. Also, because a sewing thread used for sewing the filament fastener elements having the metal coating layers to the side edges of the fastener tapes may be a sewing thread of a normal form and may be a transparent sewing thread, the slide fasteners do not have the retroreflective function at all.